fuel mileage, help

[robinsherry]

to anyone, i have just bought a 91 manual 5 speed, need too improve my milage somehow. am not even getting 400km a tank hwy driving, is there any thing i can have done to the engine. am planning to go to veg soon but would like to increase my fuel milage for now. i don't go over a hundered, and even coast down the hills.
help!

[bae146]

You may need a tune up. If you are in the lower mainland CVI is the place to go. My Pajero ran much better and burned less fuel after they were done with it. They cleaned the injectors, set the pump timing and adjusted the valves. It cost 325.00 plus tax. I needed new injector gaskets as they were toast. My truck now starts much better and uses less fuel. What tire size are you running? IF you have larger tires than stock your odometer will indicate that you are driving less distance than you actually are. Check it with a gps. I know mine is out by 6.5 percent.

[delicat]

Don't forget your manual has smaller fuel tanks and also revs higher than a auto for the same speed. (just in case you're comparing your van to someone else...). Both will decrease your km/tank.

As bae146 said, a tune up is the best start. For the long run you could definitely benefit from larger tires, especially on a manual as they'll lower your rpm.

David

[Green1]

am not even getting 400km a tank hwy driving

but what mileage are you getting?
400km tells us nothing without knowing how many litres you are using for that distance.
for all we know you could be getting better fuel economy than anyone else here... or worse, km/tank is a useless measurement. give it to us in L/100Km.

[jrman]

I've noticed quite an improvement in Highway mileage by keeping the deli between 80-90 Km/H. Mine has Auto trans and can cruise at 100 Km/H quite easily but that little 2.5L does have to work harder to keep that velocity - so now I run it a little slower and smell the roses while en route!!!!

[mararmeisto]

A couple of things:

-read this post first

-this is a post from a previous thread

2WD: 56 litres
4WD M/T: 60 litres
4WD A/T: 75 litres
(All indicate about 7 litres remaining when the little fuel pump light comes on.)

[quadzilla]

I too drive a manual (1992) and the 400 km mark per tank (before the fuel light starts to come on) is a good estimate, but like Green1 says, it is best to provide some measure of your fuel economy. My manual has been averaging 12.5 l / 100 km with a ton of "high speed" highway driving (range 11.2 l / 100 km - 14.1 l / 100 km). More recent numbers suggest an improvement, but I haven't entered those data yet to see if changes to my overall average are anything but marginal. The more hills between points A and B, the lower my fuel economy. I get my best fuel economy when driving at speeds between 60 and 80 kph.

Delicat refers to the fact that the manuals are geared lower than the autos - this is true, and we gear shifters will be running 200 - 300 rpms higher at 110 kph than those autophiles, so the manuals do get slightly poorer fuel economy.

I noticed an improvement after I had the engine tuned, valve timing adjusted, fuel pump overhauled, etc. etc. You could also check your tire pressure, and, as has been stated by others, consider some larger tires. With regards to the speed of these things - I know when I am "rocketing" down the highway at 120 kph, I use more fuel than when I go a more reasonable speed (like 90 - 100 kph). Remember - a poorly tuned motor will return poor fuel economy, as will matting it all the time and trying to set a North American land speed record in a Delica - drive the beast like the washing machine on wheels that it is. Based on how you have described your driving style, a tune up by a qualified and competent JDM mechanic who has worked extensively on Delicas should definitely be a priority for you.

Good Luck.

[Erebus]

What tire size are you running? IF you have larger tires than stock your odometer will indicate that you are driving less distance than you actually are. Check it with a gps. I know mine is out by 6.5 percent.

My tires are 235/75r15, so much larger than stock (largest you can put on stock rims) and my odometer is still reading 2% high.

That said, my economy (uncorrected) since I got the Delica is 12.6L/100km over 23,000 km. On my recent trip Calgary-Vancouver-Inuvik-Calgary, which included a CVI tuneup in Vancouver, I averaged 12.4 L/100km over the 10,000 km, and that is with a large roof rack with lots of stuff in the Deli. Also included lots of hills and almost 2000 km of gravel, dirt & mud that wasn't always driven in top gear.

The economy definitely went down on the last 1500 km, when we were driving 100-120 on paved roads. The rest of the time, the Deli cruised on pavement between 85-95 in the mornings to 95-110 in the afternoons.

The only way to really know your economy is to track the fillups and odometer readings, figure out your odometer error, then do the math.